vloopback

http://motion.sourceforge.net/vloopback/
The video4linux loopback device is a device driver that generates video pipes. It lets a user program feed a video stream to another as if it were coming from an actual video4linux device. To achieve this a video pipe consists out of two video4linux devices: one for the generating program to write its data to and one for a normal video4linux program to read from. At the moment there are only a few programs that can feed the input of the pipe: invert and resize, the example programs with the driver and motion, a motion detection program.

The copyright and license notices on this page only apply to the
text on this page. Any software or copyright-licenses or other
similar notices described in this text has its own copyright notice
and license, which can usually be found in the distribution or license
text itself.